1. Technical Field
The present invention relates to a method of conveying articles on a machine for filling capsules with at least one pharmaceutical product.
More specifically, the present invention relates to a method of conveying articles, each defined by a capsule comprising a bottom shell and a top shell closing the bottom shell, or by the bottom shell of a capsule, or by the top shell of a capsule. In the following description, the articles referred to are top shells of capsules, to which reference is made purely by way of example.
2. Description of the Related Art
In the pharmaceutical industry, a machine is known for filling capsules, each comprising a bottom shell, and a top shell closing the bottom shell.
The machine normally comprises a first wheel for correctly positioning the capsules vertically, with the top shells on top of the relative bottom shells, and for opening the capsules; a conveyor line for receiving the bottom shells from the first wheel and feeding them through at least one filling station; a second wheel for receiving the top shells from the first wheel; and a third wheel for receiving the bottom shells from the conveyor line and the top shells from the second wheel to close each bottom shell with the relative top shell.
The second wheel is connected to the first and third wheel at respective transfer stations, has at least one seat for a top shell, and is mounted to rotate continuously about a respective longitudinal axis to feed the seat through the transfer stations.
The seat is normally connected to a pneumatic suction device, which allows the seat to receive the top shell from the first wheel and feed it between the transfer stations, and which is deactivated to permit transfer of the top shell from the seat to the third wheel.
Known capsule filling machines of the type described above have various drawbacks, mainly due to the pneumatic suction device making the machines relatively complex, bulky, and expensive.
Known capsule filling machines of the type described above also have a further drawback when filling capsules with a powdered pharmaceutical product. That is, to prevent the powdered pharmaceutical product dispersed inside the machine from being inhaled by maintenance and cleaning personnel at the end of each operating cycle of the machine, the pharmaceutical produce is stabilized by a water spray, the effectiveness of which, however, is seriously impaired by the action of the pneumatic suction device, which tends to retain part of the pharmaceutical product inside the machine.